1. Technical Field
The present invention relates to a method of optical interconnection for optical transmission between a printed circuit board (xe2x80x9cPCBxe2x80x9d) daughter card and PCB backplane or midplane. More particularly, the present invention describes a method of turning a polymer wave-guide at a right angle at the PCB daughter card-PCB backplane/midplane interface using a technique that maintains wave-guide alignment.
2. Background Art
Optical wave-guides are generally constructed with a core of a light transmissible material and one or more cladding layers. The core may be made of synthetic plastic or polymer or a glass material. Additionally, the choice of core and cladding materials determine whether the wave-guide member is flexible or rigid.
Optical interconnect technology lacks reliable and cost effective method for turning a known wave-guide member at a right angle for the purpose of optical interconnection between a PCB daughter card and PCB backplane. The present invention offers an efficient solution for ninety degree bending and re-alignment of a flexible polymer wave-guide.
While the above cited references introduce and disclose a number of noteworthy advances and technological improvements within the art, none completely fulfills the specific objectives achieved by this invention.
The present invention consists of a right-angle turn in a polymer optical wave-guide layer that has at least one cladding layer of a lower index of refraction material on both sides (above and below) or surrounding the core element.
Two angled cuts are machined, using micro-machining techniques such as etching or laser ablation, through the top cladding layer and the wave-guide located in the middle or center layer. The angles are of a magnitude that will sum to ninety degrees total at the two joints when the top three layers are bent so that the angled faces are joined.
The angle of the cuts will be such that two joints of forty-five degrees each will be created on either side of a middle pivot piece. Thus a reflective angled surface is created such that the light propagating through the wave-guide is reflected and turned at a right angle.
These and other objects, advantages and features of this invention will be apparent from the following description taken with reference to the accompanying drawings, wherein is shown the preferred embodiments of the invention.